I was attracted to an advertisement for a Teeth Whitening product. A free trial was offered with payment of $4.95 for S&H on a credit card. The company used this information to charge $139.99 to the card for further two boxes which I promptly sent back by registered post. But I had great difficulty in contacting the company for crediting back the amount. This company is clearly fruadulant and I am worried about being further charges made to my card. Can any suggest what I can do?

A Poor Retiree.